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1 – 2 of 2Ting Li, Junmiao Wu, Junhai Wang, Yunwu Yu, Xinran Li, Xiaoyi Wei and Lixiu Zhang
The purpose of this article is to prepare graphene/polyimide composite materials for use as bearing cage materials, improving the friction and wear performance of bearing cages.
Abstract
Purpose
The purpose of this article is to prepare graphene/polyimide composite materials for use as bearing cage materials, improving the friction and wear performance of bearing cages.
Design/methodology/approach
The oil absorption and discharge tests were conducted to evaluate the oil content properties of the materials, while the mechanical properties were analyzed through cross-sectional morphology examination. Investigation into the tribological behavior and wear mechanisms encompassed characterization and analysis of wear trace morphology in PPI-based materials. Consequently, the influence of varied graphene nanoplatelets (GN) concentrations on the oil content, mechanical and tribological properties of PPI-based materials was elucidated.
Findings
The composites exhibit excellent oil-containing properties due to the increased porosity of PPI-GN composites. The robust formation of covalent bonds between GN and PPI amplifies the adhesive potency of the PPI-GN composites, thereby inducing a substantial enhancement in impact strength. Notably, the PPI-GN composites showed enhanced lubrication properties compared to PPI, which was particularly evident at a GN content of 0.5 Wt.%, as evidenced by the minimization of the average coefficient of friction and the width of the abrasion marks.
Practical implications
This paper includes implications for elucidating the wear mechanism of the polyimide composites under frictional wear conditions and then to guide the optimization of oil content and tribological properties of polyimide bearing cage materials.
Originality/value
In this paper, homogeneously dispersed PPI-GN composites were effectively synthesized by introducing GN into a polyimide matrix through in situ polymerization, and the lubrication mechanism of the PPI composites was compared with that of the PPI-GN composites to illustrate the composites’ superiority.
Peer review
The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-12-2023-0415
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Keywords
Hui Zhao, Shunzhen Ren, Zhengbo Zhong, Zhipeng Li and Tianhui Ren
This study aims to reveal the tribological mechanism of synergistic effect between MoDTC and P-containing additives in aluminum-based grease.
Abstract
Purpose
This study aims to reveal the tribological mechanism of synergistic effect between MoDTC and P-containing additives in aluminum-based grease.
Design/methodology/approach
The authors prepared a molybdenum dialkyl dithiocarbamate (MoDTC) and revealed the tribological mechanism of synergistic effect between MoDTC and P-containing additives in aluminum-based grease by combining with ZDDP and P-containing and S-free additives.
Findings
The MoDTC the authors prepared has good friction-reducing and anti-wear properties in aluminum-based grease and has an obvious synergistic effect with ZDDP. MoDTC and ZDDP have a significant synergistic effect on the tribological properties in aluminum-based grease, mainly because of the formation of phosphates and metaphosphates as well as more MoS2 in the friction film. P element plays a facilitating role in the chemical conversion of MoDTC to MoS2.
Originality/value
The experiments of MoDTC with tributyl phosphate and trimethylphenyl phosphate confirm that the P element plays a facilitating role in the chemical conversion of MoDTC into MoS2.
Peer review
The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-12-2023-0410
Details